In some adjustable shade installations, including some installations in conventional vertically disposed window openings as well as installations in skylights and sun roofs where the opening is inclined to the vertical or even horizontal, it is desirable to guidably support the shade and the movable intermediate rail during movement of the shade between an open and closed position. It has been proposed, for example as disclosed in U.S. Pat. Nos. 1,289,281 and 1,663,819, to provide adjustable shades in which guide cords are tensioned between two fixed headrails at opposite sides of the window opening and extend through a set of tension cord openings to guide the shade and rail during movement between open and closed positions, and in which draw cords are attached to the movable rail and extend through draw cords are attached to the movable rail and extend through draw cord openings that are separate from the tension cord opening to effect movement of the intermediate rail and shade between open and closed positions. It has also been proposed, for example as disclosed in U.S. Pat. Nos. 3,721,285 and 4,557,309 to arrange the draw cords and tension cords so that both extend through the same openings in the shade and headrails and intermediate rail. However, when the tension cords and draw cords extend through the same openings, problems are sometimes encountered with interference between the draw and tension cords which not only obstructs movement of the shade but also increase wear on one or the other of the cords.
In the draw cord arrangement disclosed in the above-mentioned patents, the draw cords are adapted to pull the intermediate or movable rail toward a raised position, and a cord lock or cord tie is provided for holding the intermediate rail in an adjusted position. However, such draw cord arrangements are not suitable for use in applications where the window opening is horizontal or so close to horizontal that the intermediate rail cannot be gravity actuated to its lower position.